в 16:40, 26 мая 2010

2010-05-26T16:40:06Z

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2010-05-26T12:44:43Z

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==Odbc Connection Demo==

<source lang="vbnet">
Imports System
Imports System.Data
Imports System.Data.Odbc
Module OdbcProvider
Sub Main()
" Set up connection string
Dim ConnString As String = "dsn=NorthwindOdbc"
" Set up query string
Dim CmdString As String = "SELECT * FROM employees"
"Declare Connection and DataReader variables
Dim Conn As OdbcConnection
Dim Reader As OdbcDataReader
Try
"Open Connection
Conn = New OdbcConnection(ConnString)
Conn.Open()
"Execute Query
Dim Cmd As New OdbcCommand(CmdString, Conn)
Reader = Cmd.ExecuteReader()
"Display output header
Console.WriteLine("Querying database {0} with query {1}" & _
ControlChars.NewLine, Conn.Database, Cmd.rumandText)
Console.WriteLine("FirstName" & ControlChars.Tab & "LastName")
"Process The Result Set
While (Reader.Read())
Console.WriteLine(Reader("FirstName").PadLeft(9) & _
ControlChars.Tab & Reader(1))
End While
Catch ex As Exception
Console.WriteLine("Error: {0}", ex)
Finally
"Close Connection
Reader.Close()
Conn.Close()
End Try
End Sub
End Module

</source>

==Use command parameter for Odbc connection==

<source lang="vbnet">
Imports System
Imports System.Data
Imports System.Data.Odbc
Module CommandOdbcExample
Sub Main()
Dim thisConnection As New OdbcConnection _
("dsn=MyOdbc")
Dim nonqueryCommand As OdbcCommand = thisConnection.CreateCommand()
Try
thisConnection.Open()
Console.WriteLine("Connection Opened")
nonqueryCommand.rumandText = "CREATE TABLE MyTable " & _
"(MyName VARCHAR (30), MyNumber integer)"
Console.WriteLine("Executing {0}", _
nonqueryCommand.rumandText)
Console.WriteLine("Number of rows affected : {0}", _
nonqueryCommand.ExecuteNonQuery())
nonqueryCommand.rumandText = "INSERT INTO MyTable VALUES (?, ?)"
nonqueryCommand.Parameters.Add("@MyName", OdbcType.VarChar, 30)
nonqueryCommand.Parameters.Add("@MyNumber", OdbcType.Int)
" Prepare command not supported in ODBC
" nonqueryCommand.Prepare()
" Data to be inserted
Dim names() As String = {"Z", "S", "J", "D"}
For i As Integer = 1 To 4
nonqueryCommand.Parameters("@MyName").Value = names(i - 1)
nonqueryCommand.Parameters("@MyNumber").Value = i
Console.WriteLine("Executing {0}", _
nonqueryCommand.rumandText)
Console.WriteLine("Number of rows affected : {0}", _
nonqueryCommand.ExecuteNonQuery())
Next i
nonqueryCommand.rumandText = _
"SELECT MyName, MyNumber FROM MyTable"
Dim thisReader As OdbcDataReader = nonqueryCommand.ExecuteReader()
While (thisReader.Read())
Console.WriteLine("Name and Number: {0} {1}", _
thisReader.GetValue(0), thisReader.GetValue(1))
End While
thisReader.Close()
nonqueryCommand.rumandText = "DROP TABLE MyTable"
nonqueryCommand.ExecuteNonQuery()
Catch ex As OdbcException
" Display error
Console.WriteLine("Error: " & ex.ToString())
Finally
" Close Connection
thisConnection.Close()
Console.WriteLine("Connection Closed")
End Try
End Sub
End Module

</source>

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в 16:40, 26 мая 2010

Admin: 1 версия